iTunes Connect - Issues

On Macbook Pro10.10.5 (14F27)

Chrome last version 45.0.2454.101 (64-bit)

Safari Version 9.0 (10601.1.56.2)

I try to upload an app into the AppStore via iTunes Connect.

Everything is informed (new texts, new keywords, app icons, ...) and the new build is correctly uploaded and ready to be submitted.

But when it comes to update and save screenshots it loads infinitely (loading loop) and disconnect me all of the sudden.

Basically it took me 3 hours to update 10 screenshots and texts and save everything in iTunes Connect......

After 5minutes waiting for the saving process to finish I abort it by clicking on the "Features" / "TestFlight" / "Activity" tabs (which redirect me to the corresponding pages). When I click back on the "Appstore" tab it logs me out, I login again and see the screenshots uploaded by magic...

I checked if it wasn't a network issue (Ethernet and WiFi), and it's not.

Are there other people seeing or experiencing it?